The invention concerns a process and an apparatus for activating, reactivating or regenerating a solid catalyst for the treatment or conversion of hydrocarbons.
The catalyst treated according to the invention is used as solid particles, these particles being of various shapes such as balls, crushed materials, extrudates, pellets, etc.
The activable, reactivable or regenerable catalysts according to the invention are particularly the catalysts for the treatment, hydrotreatment, visbreaking and conversion or hydroconversion of hydrocarbons and/or hydrocarbon cuts of various origins; examples of hydrocarbon cuts are liquid charges obtained from distillates of heavy crude oils, residues from the straight-run or vacuum distillation of hydrocarbons obtained from effluents of coal liquefaction etc. Mention will also be made of liquid charges of oil origin or of a different origin, to be subjected to any one of the treatments selected for example from dehydration, hydrosulfurization, hydrodenitrogenation, desulfurization, hydrodesulfurization, dehydrohalogenation, reforming, reactions for producing aromatic hydrocarbons, steam reforming, cracking, hydrocracking, hydrogenation, dehydrogenation, isomerization, dismutation, oxychlorination, dehydrocyclization of hydrocarbons or other organic compounds, oxidation and/or reduction reactions, Claus reaction, treatment of the exhaust gases from internal combustion engines, demetallation, etc.
During such catalytic treatments, a rather quick deactivation of the catalyst is observed as a result of the presence of catalyst poisons, coke formation, deposit of certain metals, etc. This deactivation requires a frequent replacement of the whole or a part of the catalytic bed.
The catalyst contains, as basic material, at least one oxide of a metal (e.g. aluminum) or metalloid (e.g. silicium). Actually, the catalyst is constituted of (a) a carrier (or matrix) whose basic material is said oxide and (b) an active phase containing at least one metal, optionally with metal precursors or promoters.
Examples of carriers are all kinds of aluminas, either silicas, either silicas-aluminas, all these various oxides being used in amorphous state or in crystallized state (zeolites) or still as a mixture of amorphous and crystallized oxides. Further examples of oxides which can be used as carriers, either alone or in admixture, are magnesias, bauxites, clays, kieselguhrs, silicas-magnesias, aluminas-magnesias, boron-aluminas, etc.
Practically all the metals of the periodic classification of elements can be used as active phase of the catalyst and, particularly, either alone or in admixture, iron, cobalt, nickel, tungsten, molybdenum, copper, silver, gold, the noble metals of the platinum family, germanium, tin, lead, indium, thallium, titanium, rhenium, manganese, chromium, vanadium, etc. These metals are used, for example, either directly as metals or as oxides or sulfides (particularly cobalt, molybdenum, tungsten, nickel and iron oxides and sulfides).
The activation or reactivation or regeneration of the catalysts generally requires at least one step of heating the catalyst to remove from each catalyst grain or particle at least one type of impurities. Thus, for example, the catalysts which have been used in reactions of desulfurization or hydrodesulfurization of hydrocarbons contain substantial amounts of sulfur and carbon, elements which have to be removed before the re-use of the catalyst.